Leaky Gut Syndrome: Causes, Treatments and Prevention

Leaky gut word cloud

Last Updated: October 3, 2023

The condition known as leaky gut syndrome has been gaining a lot of attention recently, especially among natural health advocates. Leaky gut is a digestive disorder that allows bacteria and toxins to “leak” through the wall of the intestines.

However, the medical establishment does not consider leaky gut a real condition. Even so, there is a lot of scientific evidence that suggests that leaky gut exists and can be linked with multiple health conditions.

This article examines the evidence regarding leaky gut syndrome.

What is Leaky Gut?

The digestive tract is where foods get broken down and nutrients are absorbed into the body. Your body is protected from harmful substances by the digestive system by the walls of your intestines, which act like barriers to keep harmful substances from entering your bloodstream and reaching the organs.

Tight junctions are small gaps in the intestinal wall that allow nutrients and water to pass through. They also block harmful substances from passing through. Intestinal permeability is the ability to allow substances through the intestinal wall.

The gut can become more permeable if the tight junctions between intestinal walls loosen. This may allow bacteria or toxins to enter the bloodstream, a phenomenon often referred to as “leaky gut”.

If the gut becomes “leaky”, bacteria and other toxins can enter the bloodstream and cause inflammation. This could possibly trigger an immune response.

Leaky gut syndrome is thought to cause bloating, food sensitivities, fatigue, skin conditions, and more. However, leaky gut is not considered a medical diagnosis, and some healthcare practitioners even deny that it exists at all.

Nevertheless, it is believed by many to be the cause of numerous conditions, such as chronic fatigue syndrome (CFS), multiple sclerosis (MS), fibromyalgia, food allergies, thyroid issues as well as autism and mood swings.

Unfortunately,  there is currently not lot of research into leaky gut syndrome. And yet, doctors do agree that certain chronic diseases can cause an increase in intestinal permeability, or hyperpermeability.(1)

Chart depicting the differences between a healthy gut and a leaky gut.
Healthy intestinal walls compared to permeable walls.

What causes leaky gut?

The cause of leaky gut syndrome is still a mystery that medical researchers are trying to figure out. The only known regulator of intestinal permeability is a protein called zonulin.(2)

Zonulin can cause leaky gut in people who are genetically predisposed to it. The two main contributors that can cause zonulin to be released in your gut are intestinal bacteria and gluten. Gluten is a protein found mostly in grains, such as wheat.

Some research, however, indicates that gluten only increases intestinal permeability for people suffering from conditions such as celiac disease and IBS (irritable bowel syndrome).(3) It is likely that leaky gut syndrome can be caused by many factors.

Here are some of the factors that may play a part:

  • Consuming Too Much Sugar – A diet high in sugar, especially fructose, can harm the intestinal barrier function.
  • NSAIDs (Non-steroidal Anti-Inflammatory Drugs) – Long-term use of drugs such as ibuprofen can cause intestinal permeability lead to a leaky gut.
  • Consuming Too Much Alcohol – Drinking an excessive amount of alcohol can increase intestinal permeability.
  • Nutritional Deficiencies: Deficient amounts of zinc and vitamins A and D have been linked to increased intestinal permeability.
  • Inflammation – Long-term inflammation throughout the body may lead to leaky gut syndrome.
  • Stress – Prolonged stress can lead to many gastrointestinal conditions including leaky stomach.
  • Bacterial Imbalance: There gut contains millions of bacteria, both beneficial and harmful. If the balance between these two types of bacteria is disturbed, it can decrease the effectiveness of the intestinal wall barrier.
  • Yeast Overgrowth: Although yeast is naturally found in the intestines, an excessive amount of it can cause leaky gut.

Conditions Caused By a Leaky Gut

Science has not yet proven that leaky gut is responsible for health problems. That said, many studies have linked an increased intestinal permeability to several chronic diseases.(4)

Celiac Disease

Celiac disease, is an autoimmune condition resulting from a severe allergy to gluten. Numerous studies have shown that celiac patients have higher intestinal permeability.

One study actually found that gluten consumption significantly increased intestinal permeability in celiac patients within minutes of eating.(5)


Some evidence suggests that type 1 diabetes can be linked to increased intestinal permeability. Type 1 diabetes is caused when insulin-producing beta cells in your pancreas are destroyed by an auto immune response.

The immune response that kills beta cells may be caused by toxic substances “leaking” through the gut. Additionally, one study showed that 42% of type 1 diabetics had significantly higher levels of zonulin. Zonulin has been shown to be a regulator for intestinal permeability.(6)

Another study revealed that rats with diabetes had abnormal intestinal permeability before they developed.

Crohn’s Disease

In Crohn’s disease, increased intestinal permeability is a key factor. Crohn’s disease is a chronic condition that causes chronic inflammation in the intestinal tract.

Numerous studies have shown greater intestinal permeability in Crohn’s patients, and some studies also showed an increase in intestinal permeability among relatives of Crohn’s patients.(7) This suggests that Crohn’s may be linked to increased permeability.

Irritable Bowel Syndrome

IBS is a digestive disorder that causes constipation and diarrhea. Studies have shown that IBS sufferers are more likely to have higher intestinal permeability .

One study showed that IBS sufferers with diarrhea-predominant IBS have an increased intestinal permeability.(8)

Allergies to Food

Some research shows that people with food allergies frequently have impaired function of the intestinal barrier.(9) Leaky guts can permit food proteins to pass the intestinal barrier and trigger an immune response.

Does Leaky Gut Cause Disease?

According to many, the root cause of most health problems is due to leaky gut syndrome. And numerous studies have demonstrated that intestinal permeability increases in many chronic diseases, primarily autoimmune disorders.

But it is difficult to prove that the main cause for disease for these conditions is a leaky gut. Skeptics contend that an increase in intestinal permeability is a sign of chronic disease, not the other way around.

It is interesting to note, however, that animal studies on type 1 diabetes, IBS, and celiac disease have shown an increase in intestinal permeability before the onset of illness.(10) This research lends credence to the theory that disease can be caused by leaky gut.

Conversely, one study showed that most celiac disease sufferers had intestinal permeability levels return to normal when they eat gluten-free for more than a year. Currently, following a gluten-free diet is the standard way to treat celiac Disease.

The indication is that abnormal intestinal permeability could be an effect of gluten ingestion, rather than the cause of it. There isn’t enough evidence currently to support the idea that leaky gut is the root cause of chronic disease.

Science does not support some claims about Leaky Gut Syndrome

Evidence is sufficient to prove that leaky gut syndrome exists, but some claims are not supported by science.

Leaky gut advocates claim that it is linked to many conditions, including anxiety, depression, eczema, autism, and cancer. Scientific research has not yet supported most of these claims.

Although some studies found an increase in intestinal permeability in autistic children, others have shown normal intestinal permeability.(11)

There is currently no research showing leaky gut prior to the development of autism. This means that there is no current proof that it is a contributing factor.

Some evidence suggests that bacteria may pass the intestinal wall leading to anxiety and depression. However, further research is necessary.

Studies seeking to link eczema and intestinal permeability have not produced consistent results, and no evidence currently exists that shows leaky gut may contribute to cancer.

Steps to Improve Gut Health

Leaky gut syndrome does not constitute a medical diagnosis. There is no standard recommended treatment.

However, there are still steps you can take that will improve your gut health. For example, one way a healthy gut can be achieved is by increasing the amount of beneficial bacteria.

Here are some strategies to help promote a healthy gut:

  • Reduce Intake of Refined Carbs – Harmful bacteria feed on sugar, and too much sugar in the diet can lead to poor barrier function.
  • Consider Using Probiotics – Probiotic supplements can help improve your digestive health. Probiotics have been proven to be helpful in treating gastrointestinal disorders..
  • Eat more fermented foods: Gut-friendly foods such as sauerkraut, yogurt, kefir, kimchi, and kombucha all contain probiotics that are beneficial to gut health.
  • Increase Fiber Intake –  The type of soluble fiber found in fruits, vegetables, and legumes, is a prebiotic, meaning it feeds the good bacteria in your digestive tract.
  • Limit the usage of NSAIDs – Leaky gut syndrome can be caused by long-term NSAID use.
  • Take Supplements to Improve Gut Health There are several all-natural supplements available that help you to clean, detoxify, strengthen, and support the intestines.

The bottom line

Leaky gut syndrome is a condition where bacteria and toxins can pass through the wall of the intestines into the bloodstream. Although some healthcare professionals may deny the existence of leaky gut, there is plenty of evidence to support it.

For instance, leaky gut syndrome is a common occurrence with autoimmune disorders. But there currently isn’t adequate evidence to suggest that leaky gut syndrome may be the reason for these conditions.

You can reduce your risk of developing leaky gut syndrome by improving your gut health and eating a healthy diet.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856434/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3458511/
  3. https://www.ncbi.nlm.nih.gov/pubmed/16099460
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3458511/
  5. https://www.ncbi.nlm.nih.gov/pubmed/16099460
  6. https://www.ncbi.nlm.nih.gov/pubmed/16644703/
  7. https://www.ncbi.nlm.nih.gov/pubmed/3777713/
  8. https://www.ncbi.nlm.nih.gov/pubmed/16771951
  9. https://www.ncbi.nlm.nih.gov/pubmed/16880015/
  10. https://www.ncbi.nlm.nih.gov/pubmed/10198339/
  11. https://www.ncbi.nlm.nih.gov/pubmed/20683204
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